After three years of construction, and 14 years since the planning process began, the largest desalination plant in the U.S. (and all of the Western hempisphere) opened this week in Carlsbad. Named the Claude “Bud” Lewis Desalination Plant, after the recently deceased long time mayor of Carlsbad who was a major player in having the city be the location for the plant.
The plant is built beside the Agua Hedionda Lagoon next to the Encina Power Station on about 6 acres of land. It operates as a private-public partnership. The plant, owned by Poseidon Water, sells the desalinated water to the San Diego County Water Authority.
Desalination is the term for the process of removing minerals (typically salt) from water. The plant in Carlsbad uses a specific type of filtering called reverse osmosis to remove the salt. Due to high costs, the process is not very popular compared to other ways of obtaining fresh water. Currently only around 1% of the world’s population depends on desalinated water. As sources continue to be depleted, that number will need to increase quickly, however. Israel is currently the country with the highest percentage of it’s water coming from desalination, at 40%.
The plant will be pumping approximately 50 million gallons of water to the San Diego County Water Authority every day, enough to fully supply 400,000 San Diegans with water. That’s about 10% of the total use of the city.
The process of desalination isn’t perfect, however, as it takes about 2 gallons of sea water for one gallon of fresh water. It is also more expensive than other sources of fresh water. San Diego residents can expect to see an average increase on their water bill of about $5. Long term, the
A majority (64%) of the water San Diego uses currently is imported from the Colorado River. Only about 10% of the total usage comes from local sources. With the new plant operating at full capacity, the local production will increase to about 25%.